GB659995A - Improvements in or relating to sewing machines - Google Patents

Abstract

659,995. Eccentrics. FAIRWEATHER, W. C. (Singer Manufacturing Co.). July 18, 1947, No. 19225. [Class 122(i)] [Also in Group VII] An adjustable eccentric for use in sewing-machines, particularly for varying the feed, comprises inner and outer eccentrically-apertured cylindrical members on a shaft, with adjusting means comprising a motion-modifying linkage connecting the shaft with one of the members or connecting the members; the linkage causes greater relative movement between the two members than between either member and the shaft and thus reduces or eliminates the shift of the high point of the eccentric relative to the shaft. In the form shown in exploded view, the shaft (not shown) has fixed to it members 50, 44 and carries between these members the inner eccentric member 56, on which the outer eccentric member 59 is mounted. The member 50 has a transverse channel to receive a slidable member 53 with forks 67. 68 to engage respectively a part 66 integral with the member 59 and a shoe 64 mounted on a pivot pin 62 on the member 56; these parts constitute the motion-modifying connection hetween the shaft and the outer member 59, by which any movement of the shaft relative to the inner member 56 results in greater movement of the member 59. The members are normally locked together by a detent 71 slidable in a guide on a disc 69 integral with the member 56 to engage a toothed ring 75 housed in flanges 70 of the disc and locked to the member 44; to adjust the eccentric a plunger (not shown) is depressed to engage a notch 82 in the detent 71, thus locking the disc 69, and force its teeth clear of the ring 75, rotation of the shaft then producing relative movement between the members 59, 56 as stated. A modification is referred to in which the locking device is applied to the outer eccentric member 59 instead of the inner one.